<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>
@counter-style mycounter {
  system: cyclic;
  suffix: " ";
  symbols: url(./resources/1.bmp) url(./resources/2.bmp) url(./resources/3.bmp);
  symbols: Ⓐ Ⓑ Ⓒ Ⓓ Ⓔ Ⓕ Ⓖ;
}
</style>
<style>
ol {
  list-style: mycounter;
}
</style>
</head>
<body>
<ol>
  <li>item1
  <li>item2
  <li>item3
  <li>item4
  <li>item5
  <li>item6
  <li>item7
  <li>item8
  <li>item9
  <li>item10
</ol>
</body>
</html>
